<?php
/**
 * CJavaScript helper class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CJavaScript is a helper class containing JavaScript-related handling functions.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CJavaScript.php 2799 2011-01-01 19:31:13Z qiang.xue $
 * @package system.web.helpers
 * @since 1.0
 */
class CJavaScript
{
    /**
     * Quotes a javascript string.
     * After processing, the string can be safely enclosed within a pair of
     * quotation marks and serve as a javascript string.
     * @param string $js string to be quoted
     * @param boolean $forUrl whether this string is used as a URL
     * @return string the quoted string
     */
    public static function quote($js,$forUrl=false)
    {
        if($forUrl)
        return strtr($js,array('%'=>'%25',"\t"=>'\t',"\n"=>'\n',"\r"=>'\r','"'=>'\"','\''=>'\\\'','\\'=>'\\\\','</'=>'<\/'));
        else
        return strtr($js,array("\t"=>'\t',"\n"=>'\n',"\r"=>'\r','"'=>'\"','\''=>'\\\'','\\'=>'\\\\','</'=>'<\/'));
    }

    /**
     * Encodes a PHP variable into javascript representation.
     *
     * Example:
     * <pre>
     * $options=array('key1'=>true,'key2'=>123,'key3'=>'value');
     * echo CJavaScript::encode($options);
     * // The following javascript code would be generated:
     * // {'key1':true,'key2':123,'key3':'value'}
     * </pre>
     *
     * For highly complex data structures use {@link jsonEncode} and {@link jsonDecode}
     * to serialize and unserialize.
     *
     * @param mixed $value PHP variable to be encoded
     * @return string the encoded string
     */
    public static function encode($value)
    {
        if(is_string($value))
        {
            if(strpos($value,'js:')===0)
            return substr($value,3);
            else
            return "'".self::quote($value)."'";
        }
        else if($value===null)
        return 'null';
        else if(is_bool($value))
        return $value?'true':'false';
        else if(is_integer($value))
        return "$value";
        else if(is_float($value))
        {
            if($value===-INF)
            return 'Number.NEGATIVE_INFINITY';
            else if($value===INF)
            return 'Number.POSITIVE_INFINITY';
            else
            return rtrim(sprintf('%.16F',$value),'0');  // locale-independent representation
        }
        else if(is_object($value))
        return self::encode(get_object_vars($value));
        else if(is_array($value))
        {
            $es=array();
            if(($n=count($value))>0 && array_keys($value)!==range(0,$n-1))
            {
                foreach($value as $k=>$v)
                $es[]="'".self::quote($k)."':".self::encode($v);
                return '{'.implode(',',$es).'}';
            }
            else
            {
                foreach($value as $v)
                $es[]=self::encode($v);
                return '['.implode(',',$es).']';
            }
        }
        else
        return '';
    }

    /**
     * Returns the JSON representation of the PHP data.
     * @param mixed $data the data to be encoded
     * @return string the JSON representation of the PHP data.
     */
    public static function jsonEncode($data)
    {
        return CJSON::encode($data);
    }

    /**
     * Decodes a JSON string.
     * @param string $data the data to be decoded
     * @param boolean $useArray whether to use associative array to represent object data
     * @return mixed the decoded PHP data
     */
    public static function jsonDecode($data,$useArray=true)
    {
        return CJSON::decode($data,$useArray);
    }
}
